Superficial Intrinsic Back Muscles Splenius capitis Origin lower half of

Superficial intrinsic back muscles splenius capitis

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C. Superficial Intrinsic Back Muscles Splenius capitis Origin: lower half of ligamentum nuchae, spinous processes of C7 to T4 Insertion: mastoid process, lateral 1/3 of superior nuchal line of skull Action: laterally rotate head to ipsilateral side of active muscle; together extend head and neck Innervation: posterior rami of middle cervical spinal nerves Splenius cervicis Origin: spinous processes of T3 to T6 Insertion: transverse processes of C1 to C3 Action: laterally rotate head to ipsilateral side of active muscle; together extend head and neck Innervation: posterior rami of lower cervical spinal nerves D. Intermediate Intrinsic Back Muscles Erector spinae, a muscle group composed of the iliacostalis, longissimus & spinalis muscles. Origin: broad tendon from posterior part of iliac crest and sacrum Insertion: Iliocostalis – ribs & cervical transverse processes; Longissimus – ribs, cervical & thoracic transverse processes & mastoid process of skull; Spinalis – thoracic spinous processes Action: act alone to laterally flex vertebral column; act together to extend vertebral column & head Innervation: posterior rami of spinal nerves E. Deep Intrinsic Back Muscles Transverspinales, a muscle group composed of the semispinalis, multifidus & rotatores muscles. Origin: transverse processes of vertebrae Insertion: spinous processes of superior vertebrae Action: act alone to rotate vertebral column contralaterally; act together to extend vertebral column Innervation: posterior rami of spinal nerves Segmental muscles. Composition: levatores costarum, interspinales, intertransversarii. Origin: Levatores – transverse processes of C7 & T1-T12 vertebrae; Interspinales –spinous processes of cervical & lumbar vertebrae; Intertransversarii – transverse processes of cervical & lumbar vertebrae Insertion: Levatores – ribs; Interspinales –spinous processes of next superior vertebra; Intertransversarii –transverse processes of adjacent vertebrae Action: act to stabilize the vertebral column to maintain posture 74 © 2011 Shirley J. Wright, Ph.D.
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Innervation: posterior rami of spinal nerves LABORATORY EXERCISE 4.9 Clinical Issues This laboratory exercise helps you learn about some clinical issues related to the vertebral column. At the side lab bench are images of regions of the vertebral column with clinical issues. Be able to recognize and describe the condition. Abnormal Curvatures of the Vertebral Column Kyphosis : excessive curvature in the vertebral column causing a humpback or hunchback appearance. The vertebral column curves posteriorly. This can be caused by erosion of anterior part of vertebrae due to osteoporosis. Lordosis : excessive curvature of the vertebral column causing a hollowback or swayback appearance. This causes extension of lumbar vertebrae and an anterior tilting of the pelvis. A temporary lordosis can appear in pregnant women during late pregnancy.
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  • Spring '11
  • Masthay
  • Vertebra, Bones of the torso

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